The present invention relates to a method and apparatus for forming flat bottom bags.
In U.S. Pat. No. 3,970,241, there is disclosed a construction for a reinforced flat bottom bag having a bottom of more than one thickness. The present invention has as its main object provision of an improved method and apparatus for forming the bag disclosed in the aforementioned U.S. patent and simple apparatus for carrying out the improved method in a rapid and continuous cyclical operation.
The known prior art devices for forming flat bottom bags from relatively thin-walled plastic material are complex and extremely costly both to manufacture and to operate. In addition, they are generally incapable of producing the bags in a limited amount of space and with a degree of rapidity sufficient to render the operation economically attractive. Thus, the end costs of the flat bottom bags produced thereby are relatively high resulting in diminished sales as bag users substitute less expensive but less satisfactory bag constructions than the relatively costly flat bottom bags.
It is a particular object of the present invention to provide a method and apparatus for the production of thin-walled flat bottom bags formed of a thermoplastic material.
It is a further object of the present invention to provide a method and apparatus for forming flat bottom bags utilizing a substantially endless supply of thermoplastic material in tubular form.
Another object of the present invention is the provision of such a method and apparatus utilizing a mandrel supported internally within the tube of material and operable through the material for forming an internal abutment against which the flat bag bottom may be formed.